Printing device for calculating machines

ABSTRACT

A printing device for a calculating machine in which a reciprocable value transfer member is drivingly connected with a printing wheel, while the printing wheel is rotatably mounted on one end of a lever which is pivoted in the machine and which is spring biased toward printing position and adapted for being held in retracted position by a pawl. The pawl releases the printing lever to actuate the type wheel toward a printing position and adapted for being held in retracted position by a pawl. The pawl releases the printing lever to actuate the type wheel toward a printing roller when the value transfer member is stationary. The printing wheel remains drivingly connected with the value transfer member during movement of said lever between printing and retracted positions thereof.

United States Patent Inventor Priority PRINTING DEVICE FOR CALCULATINGMACHINES 5 Claims, 1 Drawing Fig.

U.S. Cl 235/58 P,

10 1 I93 Int. Cl G06c 29/00 Field of Search 235/58, 58

M, 58 P;101/93 M,93 MN,93 RC, 109

References Cited UNITED STATES PATENTS Primary Examiner-Richard B.Wilkinson Assistant ExaminerStanley A. Wal Attorney-Walter BeckerABSTRACT: A printing device for a calculating machine in which areciprocable value transfer member is drivingly connected with aprinting wheel, while the printing wheel is rotatably mounted on one endof a lever which is pivoted in the machine and which is spring biasedtoward printing position and adapted for being held in retractedposition by a pawl. The pawl releases the printing lever to actuate thetype wheel toward a printing position and adapted for being held inretracted position by a pawl. The pawl releases the printing lever toactuate the type wheel toward a printing roller when the value transfermember is stationary. The printing wheel remains drivingly connectedwith the value transfer member during movement of said lever betweenprinting and retracted positions thereof,

PATENTEU'UBI s IBYI INVENTOR.

ANDREAS HETSCHNA BL PRINTING DEVICE FOR CALCULATING MACHINES The presentinvention relates to a printing device for calculating machines in whichthe value transfer rack, which in moved out condition is arrested by aspring force, comprises a value which previously in conformity with thedepressed key has been sensed or felt in the pertaining mechanism. Therack transfers this value to the rotatable printing or type wheel whichis rotatably connected to a printing hammer which may selectively betiltable. The printing hammer is first held in its starting positionagainst the thrust of a spring force and after the value has beentranslated is released for printing.

Printing devices of the above-mentioned type are known. In thisconnection there may be mentioned a device in which each value stationconsists primarily of a printing hammer, a number wheel connected to atype wheel, an intermediate meshing with the number wheel and rotatablyarranged on the hammer, and a further intermediate wheel, the so-calledtransfer wheel, which meshes with the intermediate wheel on said hammer.The said transfer wheel meshes with the value transfer rack and when therack is moved from its starting position transfers the value stored inthe rack to the intermediate wheel and the number wheel. A ratchet wheelspringbiased against the number wheel will, during the printingoperation, serve for aligning purposes. For mounting the ratchet leverand the two intermediate wheels, each hammer is provided with threeextending bolts.

This device has the drawback that for the mechanically simple operationof value transfer from the rack to the type wheel or printing rollerthere are relatively many structural elements necessary. This fact andexpense complicates the maintenance of stock and increases the price ofthe finished product.

It is, therefore, an object of the present invention to provide aprinting device for calculating machines which will overcome theabove-mentioned drawbacks.

The above-mentioned drawbacks have been overcome by the device accordingto the present invention which is characterized primarily in that a typewheel rotatably connected to a preferably two-arm printing hammer andmeshing with the value transfer rack, which type wheel feels the valuecontained in the moved out gear rack and subsequently during a briefstandstill of the gear rack prints said value by a pivot movement of theprinting hammer.

According to a further development of the present invention, the typewheel is composed primarily of a sector equipped with printing types anda sector equipped with teeth. ln this way the heretofore employedintermediate wheels, the spring-bias ratching lever and the abutmentshaft as well as the intermediate gears and ratchet lever extensionbolts are eliminated so that a low safe spacing design is obtained withonly a few structural elements so that the maintenance of stock and themanufacturing costs are considerably simplified and a correspondingreduction in costs is realized. The cooperation of value transfer rackand type wheel is furthermore so designed that a special uniform linelevel of the individual printed numbers is obtained. The teeth of thegear rack and the type wheel with approximately a play of 0.3millimeters have relatively much tooth play but this play disappearsalmost completely when the type wheel engages the printing roller.

The invention is illustrated by way of example in the accompanyingdrawing, in which a value transfer rack 1 which is, by means of oblongopenings 2, guided on a bolt 3 connected to the machine, said rack beingprovided with teeth 4, 4' on opposite sides. The said rack l is engagedby one end of a tension spring 6 the other end of which is connected toa bolt 5 which, in its turn, is fixedly connected to the machine. Rack 1is shown in its basic position and with the spring 6 under tension andis held in its position by a pawl 8 on a pivot 7 which pawl iscontrolled in a standard manner. When the rack is pulled in thedirection of the arrow A against a nonillustrated abutment, the pawl 8engages a corresponding tooth space of the teeth 4. Slightly before thisengagement the pawl moves a short distance over the tooth back of thenext following tooth whereupon rt finally engages the respective toothwhereby the tooth rack will be pulled exactly into the desired position.A type wheel 10 of unitary construction meshes with the teeth 4 of rackl by means of its teeth 9. The type wheel 10 is at that side thereofwhich faces the printing roller 11 provided with printing types 12.During the displacement of the gear rack l in the direction of the arrowA, the value which was previously felt by the rack l in conformity withthe depressed key, is meshed into the type wheel. The type wheel isprovided with a bolt 13 which is rotatably journaled in the printinghammer l5 pivotable about the shaft 14. The printing hammer 15 isengaged by one end of a tension spring 17, the other end of which isconnected to a bolt 16 carried by the machine. In its basic position theprinting hammer pivoted against the thrust of the tension spring is heldby a pawl 19 mounted on a shaft 18. Since the value transfer rack 1 hasreached its predetermined end position, it remains for a brief time inthis position, and the pawl is in a manner known per se moved out of itsengagement with the printing hammer so that the latter pivots to itsdot-dash position 20. During this movement said hammer under theinfluence of a tension spring 17, presses the type wheel 10 which meshesagain with the rack so as to cause said type wheel 10 to print on thepaper strip 21 on the printing roller printing roller 1 l (dot-dashposition 22).

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular construction in the drawing, but alsocomprises any modification within the scope of the appended claims.

1. In a calculating machine having a printing roller, a type wheel ofunitary construction adjacent the roller, a lever having said type wheelrotatably mounted on one end thereof, said lever being pivotally mountedin said machine and spring biased in a direction to move said type wheeltoward said printing roller, a pawl engageable with said lever to holdit in retracted position, a reciprocable value transfer carrier meansdrivingly connecting directly to said type wheel so that movement ofsaid value transfer carrier means will rotate said type wheel, and meansfor retracting said pawl from said lever to' permit actuation of saidtype wheel into printing position while said value transfer carriermeans in engagement with said type wheel is held stationary.

2. A calculating machine according to claim 1, in which said unitaryconstructed type wheel also is provided with teeth and said valuetransfer carrier means is in the form of a rack meshing with said teeth.

3. A calculating machine according to claim 2, in which said unitaryconstructed type wheel has a sector provided primarily with thecharacters to be printed and another sector which carries said teeth.

4. A calculating machine according to claim 3, in which said rack isprovided with notches and a second pawl is provided engageable with saidnotches for locating said rack in predetermined reciprocated positionscorresponding to printing positions of said type wheel.

5. A calculating machine according to claim 4, in which said lever ispivoted between its ends in said machine and is biased toward printingposition by a spring connected to the end thereof opposite the end onwhich said type wheel is mounted at pivot point location lower thanlocation of said rack, the said pawl engageable with said lever alsobeing located at the end of said lever adjacent said spring.

1. In a calculating machine having a printing roller, a type wheel of unitary construction adjacent the roller, a lever having said type wheel rotatably mounted on one end thereof, said lever being pivotally mounted in said machine and spring biased in a direction to move said type wheel toward said printing roller, a pawl engageable with said lever to hold it in retracted position, a reciprocable value transfer carrier means drivingly connecting directly to said type wheel so that movement of said value transfer carrier means will rotate said type wheel, and means for retracting said pawl from said lever to permit actuation of said type wheel into printing position while said value transfer carrier means in engagement with said type wheel is held stationary.
 2. A calculating machine according to claim 1, in which said unitary constructed type wheel also is provided with teeth and said value transfer carrier means is in the form of a rack meshing with said teeth.
 3. A calculating machine according to claim 2, in which said unitary constructed type wheel has a sector provided primarily with the characters to be printed and another sector which carries said teeth.
 4. A calculating machine according to claim 3, in which said rack is provided with notches and a second pawl is provided engageable with said notches for locating said rack in predetermined reciprocated positions corresponding to printing positions of said type wheel.
 5. A calculating machine according to claim 4, in which said lever is pivoted between its ends in said machine and is biased toward printing position by a spring connected to the end thereof opposite the end on which said type wheel is mounted at pivot point location lower than location of said rack, the said pawl engageable with said lever also being located at the end of said lever adjacent said spring. 